1. Field of the Invention
This invention relates to a center hub holder tape holding a series of center hubs for use in a recording disc such as a magnetic disc and an optical disc.
2. Prior Art
Conventionally, in the manufacture of a magnetic disc or an optical disc, a center hub is attached relative to a center hole of a disc body by an adhesive applied to either a peripheral edge portion of the disc body around the center hole or a flange of the center hub. In such prior art, the following problems have been encountered: (1) uneven thickness of the adhesive layer due to inevitable irregularities in coating; (2) excessive care needed until the setting or curing of the coated adhesive; (3) additional treatment to deal with an excess adhesive squeezed out of the bonding area (4) inadequate bonding strength due to the starved adhesive; and (5) difficulty in detecting such inadequate bonding strength.
To overcome the above problems, another bonding method has been proposed in which adhesive rings are preformed, for example, by stamping, and are bonded onto a carrier tape at a predetermined interval, the carrier tape with the adhesive rings being wound into a roll. In the production line, the adhesive ring is applied to either the flange of the center hub or the peripheral edge portion around the center hole of the disc body to thereby bond the center hub to the disc body.
Generally, such adhesive rings are of a relative small size and therefore can not be affixed to the carried tape with a sufficient bonding strength. As a result, the adhesive rings are susceptible to peeling from the carrier tape, deformation and displacement out of position during the time when the roll-like carrier tape is moved or transported. This has affected the accuracy of positioning of the center hub relative to the disc body when assembling the recording disc, thus resulting in a very poor yield of good finish products.